The proposed research is devoted to elucidation of the mechanism by which polymorphonuclear leukocytes (PMN) stick to vascular endothelium and to each other during inflammatory stimulation. Since PMN membrane adhesiveness and degranulation are closely related following chemotactic stimulation, we propose to isolate PMN lysosomal proteins which are basically charged by copper chelate affinity chromatography and study their effects on PMN adhesion and aggregation. These proteins include lactoferrin found in specific granules and cationic proteins found in primary granules. Antibodies prepared against the proteins will be used to ascertain whether they can blunt chemotactic factor induced PMN margination and aggregation. The release of cationic proteins and lactoferrin as monitored by radioimmunoassay from rabbit and human PMNs will be related in a temporal fashion with the effects of chemotactic stimuli on the rate of PMN aggregation measured by light scattering in an aggregometer. In order to define the mechanism by which the lysosomally derived proteins promote PMN adhesion the effect of these proteins on cell surface charge will be monitored by determining the electrophoretic mobility of the cells. Similarly the kinetics of binding of these proteins to the surface of the PMN will be determined by scatchard plot analysis. Studies in rabbits will be germain in revealing whether antilactoferrin and anticationic antibodies can modify the occurrence of neutropenia following the infusion of chemotactic stimuli as well as whether the positively charged proteins can provide neutropenia. These latter studies should lead to an assessment of the interrelationships between the in vivo effects of circulating chemotactic stimuli on PMN and resulting pathological damage in animals to the interdependence among chemotaxis, degranulation, and adhesion as noted in vitro.